The 31-year-old nun, from Turin, Italy, said that she was devastated when she saw the pictures on the social networking site.
The photographs were taken in summer 2006, during a holiday in Sicily.
The man, who said that he wanted to stop her becoming a nun, has refused to remove the pictures despite the woman's requests.
And thus, the nun's lawyer Anna Orecchioni has taken the reins of the matter in her hand.
"My client doesn't want money, she only wants that he respects her decision to become a nun," the Daily Telegraph quoted her as saying.
Meanwhile, Italians are flocking the site in large numbers to see the pictures, leaving comments like: "If all the nuns are like that, I want to become a priest."